Casting-machine.



J. A. McMANUS, JR.

CASTING MACHINE; APPLICATION IILED 0012-28, 1908.

Patented Jan. 30, 1912.

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J. A. MoMANUS, JR.

CASTING MACHINE.

APPLICATION FILED 0015.28, 1908.

Patentedfian. 30, 1912.

s SHEETS-SHEET 2.

iiriesses: 1721181260 J. A. MQMANUS, JR.

GASTING MACHINE.

APPLICATION FILED our. 28, 190B.

Patented Jan. 30, 1912.

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[rave/2601; Q44 i w UNITED STATES PATENT OFFICE.

JOHN, A- memauns, .13., or 11mm; massacnusm'rs.

CASTING-MACHINE:

' Specification of Letters Patent.

Application filed October 28, 1908. i Serial No. 459,864.

- provide a casting machine. which is especially applicable to the casting of inlays, bridges, etc., for dental work, but it is realized that the same principles may be adopted to advantage in the constructiom of larger machines, and machines requiring greater energy consumption, for other purposes, such as the casting of jewelry, etc.; requiring only the adaptation of'mech'anical skill to the utilization of the principles herein involved.

F Another object of the invention is to provide an apparatus of such a construction- 7 that it will efl'ectivelyheat the material of which the casting or inlay is to be made,

and at the same time heat the mold to the.

most favorabledegree for carrying out the casting operation. p

In the case of one type of machine with whichv I am familiar, which machine has been designed for the casting of gold 'in-' lays,the gold ishfirst deposited in a receptacle in juxtaposition to a mold .of the de-; sired shape, the said receptacle communieating with the mold by a suitable sprue hole. The receptacle and mold are carried by an arm whichnis revolved by means of a clock-spring in the base of the machine.

After the gold has been=deposited in the re-' ceptacle it is heated to the desired state by playing upon it, a flame-such asan oxy-hydrogen blowflame.- The gold after being thus heatedjis then transferred into the mold by [means of thecentrifugal force developed by the revolving arm. Of course,

in thiscasethe flame has to be takenoff before the-carrier is startedrevolving. It

willbe seen, therefore, thatthe mold has to'attain its heat at the same time that the gold in the receptacle is being, heated, and

1 the mold is not heated to an amount- Where it will appreciably assist'in the casting op "eration. 1

By means oflm y improvedapparatus an electrical means is provided by virtue of which a continuous 'andat-tbe same time, a uniform heat slowly increa slng 1n -temperature is applied toboth the casting material of the employment of an electrically heated crucible having a negative temperature 00- eflicient; such material as carbon, for instance, in which case the heating is gradual, or slow and even, because the initial resistance is high but gradually falls off as the temperature increases, assuming constant potential. p

The device which is proyided by my invention is one that can readily be attached to an ordinary electrical circuit used incommercial practice, thatv is, one in which .a transformer can be connectedfor use with the machine, and such a circuit is usually available in dental oflices, laboratories, and the like. several inlays or bridges to be cast at one time,.according to the requirements of the operator. The same receptacle and flask that is used for the casting of inlays can be used in the casting of bridges, the flask "which contains the mold being of such a size" as to accommodate the bridge. In case it is desired not to use certain flasks, the metal covers of these particular flasks are taken oil, and thus the path for the electric current is interrupted at these points.

- .'My invention will be-better understood. by reference to the accompanying drawings which are merely' illustrative of certain of the forms in which my invention may be embodied, and in whichof the device shown in Fig. ,1. .Fig. 3 is a plan view of one of the'heating units and flasks employed in my improved apparatus; Fig. 4 is a vertical/section taken on the line mated Jan. 30,1912.

The machine also enables one or.

Figure. '1 is a vertical section ,taken on the. .line11 of Fig. 2-. -'Fig. 2 is,a plan view 44 of Fig. 3;"Fig. 5 is. a similar section showingthe operation of casting a' dental bridge; Fig. 6 illustrates a tooth-{provided with an inlay cast by means of'my improved '105 apparatus; Fi 7 illustratesanaturaltooth.

and an artific al'tooth bridged 'tog'ether by means of a bridge also cast by my improved device, and Fig. 8 illustrates diagraiiimatb cally the electrical connect-ions employed for I starting the motor by means of a thermostat after the gold in thereceptacles has jattained. a certain'predetern ined temperature.

'1 re resents the base of the device of my invention.- Either fastened to or cast inte- V gral with-.this base is a standard 2. Formed .1n the upper and lower portions of this standard are ball-bearing races 3 and 4 res ectively containing ball bearings 5 and 6.-

ounted soas to revolve on these ball-bearings is a hub-like member 7 having at its top, and integral therewith, a flanged por-' 10 tion -or carrier 8. Mounted upon the revolving member 7 are slip-rings 9 and 10, or what are commonly known as collector rings. The carrier 8 has mounted thereon one or several molds, as desired. In this case I 15, have shown. several molds represented by 11, 12, 13, 14, etc., communicating by means of sprue holes with receptacles 16. These receptacles may be composed of any material which will best suit the particular case where the resistance should be such as to furnish heat enough byl the passage of an electric current .throu them' to bring the gold or other materia in thereceptacles 1 6 to the proper state for casting. In the embodiment 25. of the invention herein disclosed I have shown carbon as the resistance material, but an other refractory material which will satis actprily meet the conditions is within the scope of my invention. The copper con- 0 ducting .ring 17 extends around t e lower inside faces of thecarbon receptacles and thus serves to convey current'from the con-' ducting wire to the receptacles and thence vtothe molds. Referring" now to, the electrical connections of. the device herein illustrated a'nddescribed, 18 and 19 represent brush holder studs upon-which are mounted the brushes 20 and 21. These brushes convey current to. 'and from the coll ctor rings 9' and 10 respectively. "The rush holder studs are mounted holes 22 in the base 1 and are suitably electrically insulated from said base, such as by the insulating washeri23 and 24. Nuts 25 on the studs hold the latter in place, and also serve to hold the terminal-clips 26, of the conductors 27 and 28. ,The conductors '27 and-28 are led throu h insi ilating bush- -in'gs 29.in-the base 1, t 0',t e. studs 118 and 19. A-flat copper conducting wire'30 conve s current from the collector ring 9 through t e copper conducting ring 17 to the various re- ,c'eptacles and flasks. A copper con'ductin strip 31 extends circumferentially aroun thetops-of the flasks on, the carrier 8 and v in electrical connection with said flasks, thus forming a-path for'the return circuit for the electric current. Connectedwith this metal conducting stri 31 and with the. collectorco ring 10 is anot' or copper conductin strip 32- similar to the one..-represented y 30.

. The mold 11 best illustrated in Figs. 4 and 5&5 in communication with thereceptacle 16 by means of the sprue hole 15. The mold may be made of any material suitable for a holdin means for the'flask. Each flask such purpose known to the art, such as wax, and is embedded in the investment material 33 which may be any standard investment material found in the dental market. The mold, of course, is formed .to the desired 7 shape by first making a wax impression say of the cavity in the tooth to be filled if the work in hand is an inlay, and of the shape of the mouth in oximity to the gums, if for a bridge. Th1s wax cast isthen'em'bedded in the investment material, boiled out and absorbed by the investment material, and when the gold is heated to the proper temv perature it is forced by centrifugal force to occupy the space formerly occupied by the wax.. When the gold is cooled, an 'nlay or bridge of the desired shape is th result. The flask 34 of metal is insulated by insulating material 34 of high electrical and 1 heat insulating qualities, capable of with- 35 standing extremely high temperatures; sucha material for instance as asbestos board, now on the market. This insulating material 34 is made so as to receive the carbon rece "tacle and the mold, in such manner as' to e ectually insulate them from the metal carrier 8. The flask 34 is inserted in lace. in the carrier 8, the latter being ma e of metal and so .shaped or tapered as to form is provi ed with a steel cover 35, and it is upon these steel covers and also upon the" posts 36 that the conducting strip 31 rests, the said conducting strips, of course, being suitably insulated from these posts, as by insulating washers. The steel cover 35 and thecover 35' of the receptacle 16 mallig taken ofi in one pieceas the two are together bymeans of ,the steel screwthreaded pin 37, upon theend of which is a knob 38- made preferably of heat non-con ducting material. The pins 39 which are,

provided with thumb-nuts 40 serve'to fasten down the cover to the flask 34,. While I have mentioned the pins 37 and 39 as being made of steel, they may be made of any material which will withstand the hight temeratures to which .they. are subjected. li itendingthrough the steel cover 35 and-forming a communicating passa between "the moldandfthe'outer atmosp ere is a passage 41. This passage 41 afiords a vent for the gases from the mold. When it is desired to take oil the cover the thumb-nuts 40 are unscrewed hi removes the pins 39. The 110 cover can then be pulled out from under. the conducting strip 31 bymeans of knob 38. Referrin now to'the construction show in Fig. 5,'1t is essentially the same as that shown in Fig. 3, only that 'a bridgemold is .188 shown in the flask instead of an inlay. 42 represents a orcelain facin such as is oro dina'rily emp oyed for. arti cial teeth, ex-

tendin from. which are the usual platinum pins A gold'becking 44 is placed next the porcelain facing 42, the pins 43 extending through said backing. This backing piece 44 is to prevent the hot gold from the receptacle 16' from cracking the porcelain facing which it is likely todo if the hot gold is allowed to come in direct contact with the facing. When the gold from the receptacle 16, flows into the mold 11 it is fused to the backing piece 44, around the platinum pins 43 and forms the bridge 45 to the shape of the mold. The bridge may either be cast integral with a gold crown 46, Fig. 7 which fits over the natural tooth, or the portion.45

alone may be, cast in the mold. If the latter method is employed the bridge piece 45 can, when finished and taken out of the flask, be fused to a gold band swaged around the natural tooth to which the bridgeis to be fastened.

The operation of my invention is as follows: The -material to be fused, and of which the casting' is to be made, is first placed in'thereceptacle 16. The current is then turned on by the closing ofthe main switch 47 This controls the current of the main circuit which flows through the receptacle' and heats the gold. After thegold has attained the required temperature, the carrier 8 is started revolving, either by starting-up by hand an auxiliary motor operatively connected with the pulley 48, Fig.

1; or'the machine'can bestarted automat ically by means of a thermostat in heat conductive relation with the he'atingrecepbelted or otherwise connected with the casting machine. Inthis case,- however, it will be necessary to exercise vigilance to see thatthe old or cast-ing material has attained the esired temperature before starting the power, ,whereas if this operation .isper- .formed automatically the-mechanism can be adjusted to act at the desired moment. The

automatic thermostatic regulation is accomplished in the manner illustrated in Fig.

,8 in which 11 and 16 represent the mold and receptacle respectively connected in circuit with-t-he mains .50 and 51. 49 represents the casting machine also connectedito the-mains 50 and 51 by the conductors 27 and 28 lead- 2' ing to thetaps 52 and '53 taken from the mains. .T he conductors 30 and 32 leadjrom the collector rings of the castingmachme to the conductin strips '17 and 31.- Taps 54 and 55' are ta on oil: of. the conductors 30 and 32 thus orming a. shunt to the main,

-"circuit. In this shunt circuit is the thermostat 56 and the magnet coil 57. The thermostat 56 as has been previously stated,

is in heat conductive relation with the heating receptacle. The contacting members 58 and 59 of this thermostat are normally separated and are electrically insulated from thermostat 56 is composed of two members, each member in turn comprising two different metallic pieces 61, 61 and 62, 62, the particular metals being chosen which afford the most desirable thermal couple, such as castiron and aluminum. By having the .proper arrangement of these metals as to their coetlicieuts of expansion the thermoward upon being subjected to high temperatures.

58 and 59 may complete the shunt circuit in which is the motor 63, for operating the casting machine. In order to accomplish this result in this case, therefore, if cast iron and aluminum are chosen as the desirable .metals for the thermal couple, the aluminum members will be onthe outside and the cast iron on the inside. The closing of the contacts 58 and 59 completes the shunt circuit in which also is the magnet coil 57. When this magnet coil becomes energized by the closing of the contacts 58 and 5.9, the end 64 of the pivoted switch 65 is attracted to the magnet and the end 66 68, thereby starting the motor 63, as the latter is connected by the conductors 52 and 53 with the mains 50 and 51. The motor 63 is belted or geared to the casting machine and thus operates the same, causing the gold .to beforced into the molds by centrifugal force. l'Vhen the magnet coil,57 is deenergized the end 64 of theswitch 65 drops with the assistance of the spring 69, and thus opens the motor circuit, shutting off the motor-63. The temperature at which the thermostat acts can be regulated by adjusting the screw either inward or' outward,

higher or a lower temperature, as desired.

rent through themachine: Starting with the current entering. the conductor 27, the cur rent .fiows Lto the brush holder stud 18, through the brush 20 to the collector ring 9, thro h e conducting strip 30, conducting ring '17 .to the car on receptacle '16, thence through ,theqsteel cover 35, copper conducting ring 31-, conducting strip 32, collector ring 10,-brush 21, brush holder stud 19 and out through the cohductor 28. The resistance of the receptaclesfl6, and the various electrical. proportions of theconductors,.etc.,; are so designed as to produce a degree of heat in thereceptacle suflicient to fuse the 'goldshortly after the current has been turned -on. This goldor material of which the casting is to be made is forced each other by the insulating block 60. The

stat members may bebowed inward or out-' In this case I have chosen to have them bow'inward in order that the contacts of said switch closes the contacts 67 and.

thus causing the. thermostat to act at. a-

I willnow describe the path of the cur place in the tooth 72.,

' receptacle into the'mold.

tacle duringv the casting operationl cover by the appended claims all changes suitably shaped-mold to receive, said mate- 7 rial, electrical means for initially fusing the the. receptacle .for forcing the material from combination shaped mold receptacle, electrical.

through the sprue hole 15 into the mold 11, due to the action of the centrifugal force de-. veloped by the'rev0lvingfcarrier 8; andthe pressure thus exerted upon the material inthe receptacle c'an'be regulated'by varying the rate of 'speed of the revolving-member. When this operation of casting is completed, the current is turned 01! by. turning ofi the switch 47, the power is stop ed and the machine isallowed to cool own, when. the inbld can be taken out and the cast'removed from it. \If the cast-is an inlay it can then be cemented into place in the cavity of the tooth. This is illustrated in Fig. :6, wherein 71 "represents the inlay cemented into My invention may be embodied in? man to the exact forms'shown, but intend toscope of my invention.

What I claim and desire to secure by Letters Patent of the United States, is:-'

1. In, a castin machine, thecpmbination of a rece tacle, or -the casting material, a" suitably s 'aped mold, means forheating the receptacle, and means automaticall set into operation after the material in t e receptemperatacle has attained a predetermined ture for transferring said material from the and modifications within the spirit and 2. In acasting machine, the. combination of a receptacle for the casting material, a

material in the receptacle and maintaining. the material fused during the casting op-- erat-ion, and'means for transferring the material from the rece tacle-hato the mold aft'er it hasattained the desired tempe' ure.

3. In a casting machine, the com nation of a receptacle for themastingmateri-aI, a suitably shaped lnibld, electrical means for heating'the receptacle and the mold, a sta-. tiona member, a rev'olvi (g'member suppo'rte thereby, and means ependent upon the centrifu al force developed by'the revolving mem r for 'causing thexmateri'al in the receptacle to=be forced'- nto the mold.

4.1a aggstingmachine, the combination of,a receptacle containing castin material, a mold for. receiving the materia cent-rifugal means acting onthe material while-in the latter into'tl ieim'old, and means for continuously heating; the m'oldQand the -i'ece p-' 5. In; a machine forcasting inlays, theof, a receptacle, a. suitably for receiving material fromthe,

means; for slowly and evenly heating the mold and the receptacle, and centrifugal means for forcing the ma- ,each receptacle and its terial .from the receptacle into the mold ing'means by virtue-of which the material is forced from the, receptacle intothe, mold, and conductors conveying -currentfrom a source of supply to the receptacle and mold for heating bot 7." In a machine for casting inlays, a pliirality of receptacles for castni material, a

corresponding plurality of 11101 s for recelv- 1 ing the material, means for forcing said ma terial from the receptacles-into the molds, and means for heating the material in order to fuse it said means comprising conductors 1 conveying electric current from a source of current suppl to-the receptacles and molds.- 8. In a mac ine of the character described,

the combinationof a rotating member, a plurality cf metal containing receptacles and v v molds radially arranged upon said member,

electrical means for heating all of the moldsand receptacles comprising means for conveying' current to and from the receptacles and molds, and means for rotating the re- 3 ceptacles and molds to permit the metal to 1 flow from the former to the latter under the.

action of centrifugal force. 9. In a machine for making castings, a volving carrier, a suitably sha ed mold car- .ried by said carrier, 9. receptac e also carried by the carrier for containing the material of which the casting is to be made, means for,

heating the material in the receptacle to the proper'state for casting comfprising' conductors leading from a source 0 current supply to, and'from-the receptacle andmold, and

means for forcing the material from the receptacle into the, mold.

10. In a machine for making castings,

carrier, a plurality'ef molds mounted'on said carrier, a pluralit casting material a of receptacles for the so mounted on said carrier, communidatin means between each of said receptacles an .its correspondin moldelectrical -means for heating each an revolving the carrier so asto force the material from thereceptacles into' the molds.

under the action of centrifugal force when the said material has attained the proper I means for forcgzcles into atate.-

all of said receptacles, and molds, and means for.

the castings are upon said carrier,

12. In a-machine .for making dental castings, the combination of a carrier, a plurality of. receptacles and molds radially arranged on said carrier, electrical means for heating the receptacles and molds, means for cutting out of operation one or several of the receptacles and 'molds as desired, and means for forcing the material contained in the receptacles into the molds by centrifugal action.

13. In a machine for making castings, the combination of a rotary carrier, a mold in which a dental bridge may be cast mounted a metal containing receptacle communicating with said mold, electrical means for continuously heating the receptacle and the mold, and means dependent upon the centrifugal action developed by revolving the carrier for forcing the metal from the receptacle into the mold when the said metal has'attained the proper state.

.14. In a machine of the character described, the combination of a rotary carrier, a driving' means therefor, receptacles for the material of which the casts are to be made mounted on said carrier, molds in communication with said receptacles also mounted on the carrier, means for heating the receptacles and molds, and a device for automatically starting the driving means into operation when the casting material has attained the desired temperature.

15. In a machine of the character described, the combination of a rotary carrier, a driving means therefor, receptacles for the material of which the casts are to be. made mounted on said carrier, molds in communication vwith said receptacles also mounted on the carrier, means for heating the casting materialto a high temperature, and a thermostatic device for automatically starting the driving means into operation after the casting material has become fused.

. 16. In a machine of the character described, receptacles for the material of which the casts are to be made mounted on said carrier,

molds in communication with said receptaclesalso mounted on the carrier, electrical means for heating said. receptacles and molds, a driving motor, a switch in the motor circuit, and a thermostat .which operates'to close the switch and start the motor afterthe material in the receptacles has become-fused. In a casting machine, the combination if a receptacle or the casting material, a itably s ed mold, means for heating the I a stationary member,.a revolving member supported ceptacle,

the combination of a rotary carrier,

hereby, and means dependent upon the centrifugal force developed by the revolving member for causing' the material in the receptacle to be" forced into the mold.

18. In a casting machine, the combination of a receptacle and a mold for casting material both simultaneously rotatable, with means for heating the casting material in two stages, the first stage while the machine is stationary to melt the casting material in the receptacle and the second during the transfer of the melted material from the receptacle to the mold under the centrifugal force developed by the movement of the receptacle and mold.

19. In a casting machine,

the combination of a receptacle and a mold for casting mate- I rial mounted to rotate together with means for heating both the receptacle and mold to continuously heat said material both prior to and during the casting operation.

20. The combination of tricalvfurnace, a mold movable therewith, and means for operating the furnace and mold for forcing molten material from the furnace into the mold.

21. The combination of a rotatable furnace continuously operating while in motion with a mold arranged to receive molten material from the furnace while the latter is in motion.

22. .In a casting machine, the combination of a receptacle for the casting material, a suitably shapedmold, a single means for simultaneously heating the receptacle and mold, and means for transferring the material from the receptacle into the mold. 23. Ina casting machine, the combination of a receptacle for casting material, a suitably shaped mold, means for heating the reand means controlled by the temperature for causing the material to be transferred .from the receptacle into the mold.

24:. In a casting machine, the'combination of a receptacle for the casting material, a suitably shaped mold, means for heating both the receptacle and mold, and means controlled by the temperature for causing the material to from the receptacle into the mold after said material has attained. a predetermined temperature.

In witness whereof, I have hereunto set any hand this twenty-sixth day of October I JOHN A. MGMANUS, JR. Witnesses: I g

, Faun MILLER,

CHARLES EnwrN Snimnr.

be automatically transferred a rotatable elec- 

